That error isn't exactly an OOM, it indicates the JVM is spending a significant amount of time in garbage collection.
It looks like `writer.setLength(0)` may actually allocate a new buffer, and then the buffer may also need to be resized as the String grows, so you could be creating a lot of orphaned buffers very quickly. I'm not that familiar with StringBuilder, is there a way to reset it and re-use the existing capacity? Maybe `writer.delete(0, writer.length())` [1]? [1] https://stackoverflow.com/questions/242438/is-it-better-to-reuse-a-stringbuilder-in-a-loop On Wed, Sep 2, 2020 at 3:02 PM Talat Uyarer <[email protected]> wrote: > Sorry for the wrong import. You can see on the code I am using > StringBuilder. > > On Wed, Sep 2, 2020 at 2:55 PM Ning Kang <[email protected]> wrote: > >> Here is a question answered on StackOverflow: >> https://stackoverflow.com/questions/27221292/when-should-i-use-javas-stringwriter >> <https://urldefense.proofpoint.com/v2/url?u=https-3A__stackoverflow.com_questions_27221292_when-2Dshould-2Di-2Duse-2Djavas-2Dstringwriter&d=DwMFaQ&c=V9IgWpI5PvzTw83UyHGVSoW3Uc1MFWe5J8PTfkrzVSo&r=BkW1L6EF7ergAVYDXCo-3Vwkpy6qjsWAz7_GD7pAR8g&m=mVBqxC5kNOARPduF-c17S1VnIw8gwS6alvgONJKfheY&s=ggveahdPKo3vaAhADvjz4ucjndSmzyOZ8FPBvJ_0oZQ&e=> >> >> Could you try using StringBuilder instead since the usage is not >> appropriate for a StringWriter? >> >> >> On Wed, Sep 2, 2020 at 2:49 PM Talat Uyarer <[email protected]> >> wrote: >> >>> Hi, >>> >>> I have an issue with String Concatenating. You can see my code below.[1] >>> I have a step on my df job which is concatenating strings. But somehow when >>> I use that step my job starts getting jvm restart errors. >>> >>> Shutting down JVM after 8 consecutive periods of measured GC thrashing. >>>> Memory is used/total/max = 4112/5994/5994 MB, GC last/max = 97.36/97.36 %, >>>> #pushbacks=3, gc thrashing=true. Heap dump not written. >>> >>> >>> And also I try to use Avro rather than String. When I use Avro, it works >>> fine without any issue. Do you have any suggestions? >>> >>> Thanks >>> >>> [1] https://dpaste.com/7RTV86WQC >>> <https://urldefense.proofpoint.com/v2/url?u=https-3A__dpaste.com_7RTV86WQC&d=DwMFaQ&c=V9IgWpI5PvzTw83UyHGVSoW3Uc1MFWe5J8PTfkrzVSo&r=BkW1L6EF7ergAVYDXCo-3Vwkpy6qjsWAz7_GD7pAR8g&m=mVBqxC5kNOARPduF-c17S1VnIw8gwS6alvgONJKfheY&s=eSd0NcP8fw5BOZlSXtUMRfYuGWlN-gcXENVwgCmrapY&e=> >>> >>> >>>
